The early Civilization
games had a square grid and a camera with a fixed height angle
and orientation. The user could pan in any direction, but camera
zoom and rotation was not possible. The world was made up of
two-dimensional images that were custom crafted for these camera
limitations.

The game's emphasis was on
developing and maintaining the infrastructure necessary for
building a powerful empire. Players expanded their reach by
building cities and linking them together with roads. Cities
would only thrive if they were located near resources such as
mines, forests, and fertile land for farms. If a city had enough
access to resources, it would grow and have enough left over to
build armies. Resource gathering was done invisibly by the
computer - the player would select a spot on the map to mine and
the player's resources would automatically start to increase.
Even when a city was surrounded by enemy units, these invisible
resource gatherers could go out and collect their goods.

Armies could be built and
deployed, and each game piece was able to move a certain number
of squares per turn, depending on the type of unit and the
terrain. Each game piece had to represent multiple units since
each square in the grid could only be occupied by one piece at a
time. Players had to convince themselves that they weren't
sending a single chariot into battle, but rather an entire
chariot division. Also, the game grid's rigid position system
imposed severe limitations on the types of strategies that could
be employed. Another problem was that the scale of the game was
completely meaningless. A city took up one grid space while a
handful of peasants with pitchforks required the same amount of
game space.

Multiplayer Civilization
sessions required users to take turns at the same computer.
Eventually a special version, called CivNet, allowed
players at remote computers to play against each other via a
direct modem connection.

The next game that impacted
the game industry was Warcraft II. Warcraft II
was the first RTS game to become popular, helping to define the
genre. It was not just an RTS version of Civilization,
it had to be something different.

The most notable change from
the Civilization world was that game pieces moved across
the board in real-time. In order to support real-time movement,
the rigid grid position system had to be thrown out. With the
grid gone, more reasonable game object scales could be achieved.
Rather than representing an entire city by a single grid square,
each individual building could be represented in the game. With
building placement opened up to the user, specific types of
buildings could be made. A Barracks was required to build foot
soldiers while an Ogre Pit was necessary to build Ogres. Along
with specific building types, defensive structures like walls and
guard towers could now be incorporated into the game.

Resource gathering was made
more realistic by requiring the player to command special
resource gathering units to chop down trees or mine for gold. A
player's empire could crumble if all of his or her resource
gatherers were idle or killed. Constructing buildings also
required a special builder unit to walk to the construction site
and start hammering until the building was complete.

By eliminating turn-based
play, the only way to have multiplayer battles was to support
modem and LAN play. This was the key feature to making Warcraft
II a popular game. As a single-player game, Warcraft II
was sufficiently entertaining, but as a multi-player game it was
addicting. The types of strategies that could be employed seemed
almost limitless and, because you were playing against human
opponents, every game required new strategies. The games required
creativity, guile, and a focused mind. You weren't just playing a
game against someone, you were desperately trying to out-think
and out-maneuver a cunning foe. Defeating a computer player could
never be as satisfying as disposing of your next-door neighbor's
poorly constructed defenses.

Compared to Civilization,
Warcraft II was more focused on hand-to-hand combat.
Units were animated so that players could actually see their
Ogres swinging axes and opponents receiving the blows. The pace
of the game was also significantly different. Without the
turn-based system to slow down game play, games could become
frenetic as players raced to claim resources and raise great
armies.

However, Warcraft II
did not completely discard the work of its predecessors. The
user-interface was nearly identical to that of Civilization
and the camera was still only able to pan around the 2D world.

After Warcraft II,
the pace of new innovations in the RTS genre slowed. The emphasis
focused on achieving more and more realism while maintaining a
fun playing experience. Warcraft II's fantasy,
cartoon-like atmosphere gave way to the modern-day military
context in Command & Conquer.

Game designers became
increasingly interested in incorporating real-world military
strategy into their games. One strategy that has been true since
the days of Sun-Tzu's Art of War is to attack enemies
from an elevated position. RTS games had not been able to capture
the advantages of height because the games were 2D by nature. The
first game to gain popularity that incorporated more than two
dimensions was Cavedog Entertainment's Total Annihilation.

Total Annihilation
featured a 3D rendering engine for the units, but the terrain
still consisted of pre-rendered 2D images and the camera was
still fixed at one orientation. Because of this limitation, the
game still played like a 2D RTS game.

Presently, 3D graphics
hardware is becoming somewhat standard in new computers and game
designers can now make the leap into full 3D game worlds. One
such example is Wargames by MGM Interactive.

These fully 3D games feature
free-roaming cameras that can rotate and zoom in addition to
panning. Fire and Darkness supports free camera height
angles so that the user can view the world from above, from
ground level, or anywhere in between. The 3D environments and
free cameras create an immersive virtual world that feels very
realistic when compared to 2D games like Command &
Conquer. Further realism is achieved by incorporating
inertia into the physics model of Fire and Darkness.

3D RTS games require another
dose of innovation to make the games playable. The interface that
has been present since Civilization is still apparent in
the Wargames screenshot, but new interface questions
emerge from the 3D world. How does the user control the camera
now that it has so much added freedom? What happens when the
camera is inadvertantly placed inside a 3D object such as a
mountain range?

The task of managing
interactions between game objects becomes more difficult as well.
The Fire and Darkness demo is full of laser blasts that
travel through small hills and then hit their targets. Apparently
the programmers chose not to do full polygon-level collision
detection with every object in the game. Where do developers draw
the line in terms of what is and is not an acceptable 3D mistake?

Perhaps most challenging is
that 3D games must run fast enough to be able to maintain an
acceptable frame rate. These games pride themselves on their
realism and interactivity, which demands a frame rate of at least
30 fps. At this rate the human eye cannot detect the change from
one frame to the next.

From a technological
perspective, a group of ambitious students fresh out of CS 217
could write a Civilization-style game in one semester.
However, as you march down my brief history of computer war
games, that group of students would quickly lose their ambition.
The complexity of a 2D RTS game already puts the next game on the
list, Warcraft II, out of the realm of possibility.
Factor in the additional burden of a fully 3D world and the task
would seem nearly insurmountable. Computer war games have become
increasingly realistic by becoming complex programs that require
a team of programmers to put together.